Indexing mechanism



Dec. 5, 1961 K. H. JENSEN 3,011,305

INDEXING MECHANISM Filed July 16. 1958 7 SEC 1 5 MIN j 28 44 56 HR.

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Ka/ H. Jensen INVENTOR.

GENE Y5 United States Patent 3,011,305 INDEXING MECHANISM Kaj H. Jensen, Bareville, Pa., assignor to Hamilton Watch Company, Lancaster, Pa., a corporation of Pennsylvania Filed July 16, 1958, Ser. No. 748,851 6 Claims. (Cl. 58-28) This invention relates to electric clocks and more particularly relates to an improved driving or indexing system for a battery driven electric clock of the type wherein the balance wheel serves both as the driving element and the regulating element.

US. patent to Koehler No. 2,662,366 issued December 15, 1953, shows an electric clock of the foregoing type wherein the balance wheel is used to drive a conventional train. The present invention relates to an improvement in that type of clock utilizing an improved indexing or drive system which, in conjunction with an improved train, significantly reduces the number of bearings and wheels in the train with a concomitant reduction in the cost of the clock.

It is accordingly a primary object of the present invention to provide an improved battery driven electric clock.

It is another object of the invention to provide a battery driven electric clock having an improved indexing or driving arrangement.

It is another object of the invention to provide a battery operated electric clock having an improved and unique indexing arrangement wherein the balance or drive staff is mounted at right angles to the axes of the shafts and wheels in the train.

These and further objects and advantages of the invention will become more apparent upon reference to the following specification, claims and appended drawings wherein:

' FIGURE 1 is a partial horizontal section of the clock of the present invention; I

FIGURE 2 is a view taken along 22 of FIGURE 1; and

FIGURE 3 is an enlarged view of the collar and cam shown in FIGURE 1.

Referring to FIGURE 1, there is seen a U-shaped metal member indicated generally at which provides a pillar plate 12 and bridge 14. A center staff 16 is journaled in a bearing 18 in the bridge 14 and its other end is supported by the pillar plate 12 in a manner presently to be described in further detail. The center staff carries a fourth pinion 20 having an extended shoulder 22 which is pinned to the center staff.

A center arbor 24 is mounted over the center staff and is journaled at its left and right ends respectively on the shoulder 22 and on the center staff at 26. The center arbor 24 has a cannon pinion 28 rotatably mounted thereon and this cannon pinion is provided with an elongated barrel 30 which is received in the bearing in the pillar plate 12. A resilient spring 32 is mounted in a peripheral grove 34 in the center arbor 24 and frictionally engages the cannon pinion to provide a frictional drive between the cannon pinion and the center arbor.

The fourth pinion 20 drives a third wheel 36 which, with a third pinion 40, is journaled on a pin 38 mounted in the pillar plate 12. The third pinion 40 engages the cannon pinion 28 to establish a drive to the minute hand. The center arbor 24 has a further pinion 42 formed integrally therewith and abutting the end of the barrel 30 of the cannon pinion 28.

An hour wheel 44 having an elongated barrel 46 is mounted over the center arbor and engages a pinion 48. The pinion 48 is formed integrally with a corresponding wheel 50 which is pivoted on the pin 38 and which engages the integral pinion 42. An hour hand 52 is attached to the barrel 46 on the hour wheel 44, a minute hand 54 is attached to the outer end of the center arbor 24 and a second hand 56 is attached to the end of the center staff 16. The center staff is driven by means-of a fourth wheel 58.

A setting wheel 60 is mounted on a shaft 62 slidably and rotatably mounted in an aperture 64 in the pillar plate 12 and in an aperture 66 in the dial face 68. The shaft is; urged outwardly by a spring attached to pillar plate 12 by a rivet 67.

The fourth wheel 58 is driven by the balance wheel as presently will be described in further detail, and drives the center arbor through the fourth pinion, third wheel, third pinion, cannon pinion, and flexible spring 32. The hour hand is, of course, driven by the pinion 42, wheel 50, pinion 48 and hour wheel 44. The movement may be set by depressing the shaft 62 to move the wheel 60 into engagement with the wheel 50, the spring 32 slipping to permit the hands to be set.

The fourth wheel 58 is driven by means of a cam 70 carried by a collar 72 on the balance staff 74. Referring to FIGURE 2, the balance staff 74 is pivoted in bearing 76 and 78 in plates 80 and 82 which are attached to the U-shaped frame 10 either as separate or integral parts thereof. These plates 80 and 82 extend perpendicularly to the bridge 14, so that the balance wheel 84 is disposed perpendicularly to the wheels in the train.

The balance staff 74 carries a first split washer 86 which is frictionally secured thereto. Above this washer, the collar 72 is slidably received on the balance staff and is held down by means of a spring 88, the upper end of which bears against a second split washer 90 engaged with the balance stafi 74. The collar 72 has a depending finger 92 which is slidably received in the split washer 86 to key the collar to the washer and balance staff. This permits vertical movement of the collar against the action of spring 88.

Referring to FIGURE 3, the cam 70 extends outwardly from the collar 72 in a sector-like fashion and is helically cocked as is best seen in FIGURE 2. Oil passages 94 may be provided in the collar 72 to permit the retention of oil to facilitate sliding of the collar on the balance staff 74.

Referring to FIGURE 2, a spring 96 is attached to an upstanding lug 98 on the plate 82 and supports inter-, mediate its ends a detent 100 which it forces into engagement with the teeth 102 of the fourth wheel. A contact 104 is mounted at the upper end of the spring 96 and cooperates with a second contact 106 carried by a second spring 108 mounted adjacent and parallel to the spring 96. The spring 108 is carried by an insulating block 110 and is connected by a wire 112 to one of the terminals of the coil driving the clock. This coil and the electric and magnetic arrangement of the driving mechanism is similar to that shown in the previously mentioned Koehler patent and is not described in further detail herein.

As the balance staff 74 oscillates in a counterclockwise direction, the helically cocked cam 70 engages the adjacent tooth 114 of the fourth wheel 58. The engagement is between the underside of the cam and the top of the tooth and raises the collar 72 against the action of the spring 88. The detent 100 and spring 96 holds the fourth wheel in position during this movement so that no appreciable movement of the fourth wheel occurs. As the balance staff 74 undergoes its return motion and rotates in a clockwise direction, the upper surface of the helically cocked cam 70 engages the underside of tooth 114 of fourth wheel 58 and forces this tooth up. It will be seen that this upward movement of the tooth is caused by the fact that the cam 70 cannot slide downward on balance staff 74 by reason of the engagement of collar 72 with the first split washer 86.

As the cam 70 causes a one-tooth clockwise advancement of fourth wheel 58, detent 100 on spring 96 is forced outwardly causing contacts 104 and 106 to engage. This energizes the electric drive arrangement of the clock as is explained in detail in the aforementioned Koehler patent.

It will be apparent from the foregoing that utilizing the improved index or drive arrangement of this invention, a battery driven electric clock may be produced using a smaller number of bearings and wheels than is conventional. This permits manufacture at a lower cost, diminishes the number of possible points of failure and reduces the wear and lubrication problems.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired'to be secured by United States Letters Patent is:

1. An indexing mechanism comprising a toothed wheel, an oscillating staff perpendicular to the axis of said toothed wheel, detent means resiliently holding said toothed wheel in any one of a series of equally rotationally spaced positions, a cam keyed to said staff and slidable thereon in one direction, a stop on said staff limiting motion of said cam in the other direction, and means resiliently urging said cam in the other direction against said stop, oscillation of said staff in one direction causing one surface of said cam to slide across a tooth of said toothed wheel to rotate said wheel, and oscillation of said staff in the opposite direction causing an opposed surface of said cam to slide across a tooth of said toothed wheel causing said cam to slide on said staif. 2. An indexing mechanism as set out in claim 1 Wherein said cam comprises a generally fiat sector shaped membercanted with respect to the axis of said staff.

1 3. An indexing mechanism as set out in claim 2 wherein said cam is carried by a collar slidable on said staff, a ring fixedto said staff and forming said stop, and means extending between said collar and stop to key said collar to said stop.

ing a second ring fixed to said staff and spaced from said collar on the other side therefrom from said first ring, and

a spring engaging said second ring and said collar and urging said collar into engagement with said first named ring.

5. In a battery driven clock an indexing and switching mechanism comprising, a toothed wheel, a balance staff perpendicular to the axis of said toothed wheel, a detent urged into nesting engagement between two of the teeth of said toothed Wheel by an elongated spring, an electrical contact on said spring, a second contact adjacent said first contact and engageable thereby as said toothed Wheel advances one tooth, a cam keyed to said staffand slidable thereon in one direction, a stop on said staff limiting motion of said cam in the other direction, and means resiliently urging said cam in the other direction against said stop, oscillation of said staff in one direction causing one surface of said cam to slide across a: tooth of said toothed wheel to rotate said wheel, and oscillation of said staff in the opposite direction causing an opposed surface of said cam to slide across a tooth of said toothed wheel causing said cam to slide on said staif.

6. An indexing mechanism comprising a toothed wheel, an oscillating staff perpendicular to the axis of said toothed wheel, detent means resiliently holding said toothed wheel in any one of a series of equally rotationally spaced positions, cam means keyed to said staff and slidable thereon in one direction, stop means on said shaft limiting the mo tion of said cam means in the other direction, said cam means advancing said toothed Wheel one tooth as said staff oscillates in one direction and sliding on said stafi without advancingcsaid toothed wheel as said staff oscillates in the opposite direction.

References Cited in the file of this-patent UNITED STATES PATENTS 1,106,253 Thiel Aug. 4, 1914 2,084,226 Strahm June 15, 1937 2,266,015, Fink Dec. 16, 1941- 2,601,174 Smith June 17, 1952 2,817,207 Beyner Dec. 24, 1957 

